Improving weather predictions

To improve weather forecasting, we need to know more about the water vapor content of the atmosphere. Water vapor is a key factor in cloud formation.

However, GNSS signals crossing the troposphere, which is more or less loaded with water vapor, induce delays of varying lengths. Thanks to static multi-frequency receivers, it is now possible to determine the amount of water vapour in the troposphere.

More specifically, we are interested in the integrated water vapor (IWV) column, which designates the total mass of water vapor contained in an atmospheric column of cross-section 1 m-2 over a given point and is expressed in kg.m-2 . GNSS receivers provide zenithal tropospheric delay (ZTD), from which IWV can be obtained.

The GEOSTIX-X5 is a triple-frequency GNSS receiver that is particularly well suited to this type of measurement, which requires a dense mesh with a large number of measurement points.